Purpose – To alert companies and individuals subject to regulation and investigation by the US Securities and Exchange Commission (SEC) of potential arguments to enforce time limits on enforcement actions that have heretofore commonly been ignored. Design/methodology/approach – Analyzes two cases - one recently decided and one pending - in US Courts of Appeals, explains significance of issues at stake. Findings – The Courts of Appeals for District of Columbia Circuit has recently reviewed, and the Court of Appeals for the 11th Circuit will soon decide whether statutory timing provisions effectively remove SEC power to bring enforcement actions past their deadlines, at least in some circumstances. Practical implications – Depending on the outcomes of the cases, companies and individuals may gain a new procedural defense or two against SEC enforcement actions. They may also expect the SEC to respond by more actively seeking tolling agreements, and/or being more cautious in issuing Wells notices. Originality/value – Guidance based on pending decisions interpreting US securities law, may bring regulatory adjustments to agency practice and procedure.